Logging out of an app tied to the service stranded users for over 24 hours.

Adobe Systems is struggling to restore access to Creative Cloud, its online subscription for software and services, after an outage has locked out some users for more than 24 hours. The extended glitch is preventing some of Adobe's most popular apps from being used at all.

The software maker first acknowledged the outage on Wednesday afternoon. A day later, officials posted a brief advisory that said trouble shooters had tentatively identified the cause, but the officials provided no estimate for when the problem would be resolved. There were also reports that Adobe's Forms Central service was completely down, leaving customer-created content that relies on the service inaccessible.

Adobe's advisory offered work arounds that may allow some Creative Cloud users to connect to the site during the outage. Those who haven't signed off since the outage began may find their service remains unimpaired. Anyone who is currently signed in should not sign out or update. Those who are currently signed out and cannot successfully log in should try signing in using the trial mode of their software. Those who receive a message that their trial mode has expired may be able to use their Creative Cloud apps in bonus launch state.

"If you receive a message to Renew your subscription ... then your bonus launch has expired," Thursday's advisory stated. "If your bonus launch has expired then you will be unable to utilize the Creative Cloud applications on your current computer until the outage is complete. Updates will be shared on Twitter at @AdobeCare."